Aims: The aim of the present study is to investigate the differential expression of CD44, CD47 and c-met in ovarian clear cell carcinoma (OCCC), the correlation in their expression and their relationship with the biological behavior of OCCC. Methods: We used immunohistochemistry to examine the expression of CD44, CD47 and c-met in OCCC (86 cases) and investigated the effects of the expression and interaction of these molecules on the development of OCCC. Results: CD44, CD47 and c-met expression was significantly high in OCCC. Expression of CD44 and CD47 correlated with patient surgical stage, chemotherapy resistance and prognosis (all p < 0.05), and expression of c-met correlated with chemotherapy resistance and prognosis (all p < 0.05), but did not correlate with lymph node metastasis (all p > 0.05). The surgical stage, CD44, CD47 and c-met expression were independent risk factors for OCCC prognosis (all p < 0.05). Patients with low levels of CD44, CD47 and c-met showed better survival than those with high levels (all p < 0.05). There was a positive correlation between CD44 (or CD47) and c-met, as well as between CD44 and CD47 (the Spearman correlation coefficient rs was 0.783, 0.776 and 0.835, respectively, all p < 0.01). Additionally, pairwise correlation analysis of these three markers shows that the high expression of CD44/CD47, CD44/c-met and CD47/c-met were correlated with patient surgical stage, chemotherapy resistance and prognosis (all p < 0.05), but did not correlate with lymph node metastasis (all p > 0.05). Conclusions: Expression of CD44, CD47 and c-met was upregulated in OCCC and pairwise correlation. CD44, CD47 and c-met may have synergistic effects on the development of OCCC and are prognostic factors for ovarian cancer.
ovarian clear cell carcinoma; CD44; CD47; c-met; immunohistochemistry
Background: Chemotherapy resistance is a common problem faced by patients diagnosed with epithelial ovarian cancer (EOC). Currently there are no specific or sensitive clinical biomarkers that maybe implemented to identify chemotherapy resistance and give insight to prognosis. The aim of this study is to investigate the roles of Lewis y antigen and the markers associated with cell-adhesion-mediated drug resistance (CAM-DR) in patients with EOC. Methods: 92 EOC patients who were treated with systemic chemotherapy after cytoreductive surgery were included in this analysis. Patients were divided into two groups, chemotherapy sensitive (n = 56) and resistant (n = 36). Immunohistochemical (IHC) staining for Lewis y and CAM-DR-related cell surface proteins including CD44, CD147, HE4 (Human epididymis protein 4), integrin α5, β1, αv and β3 were conducted on tissues collected during primary debulking surgery. Using multivariate logistic regressions, IHC results were compared to clinical variables and chemotherapy resistance to determine possible correlations. The relationships between IHC expression and progression-free survival (PFS) and overall survival (OS) were analyzed using Kaplan–Meier method and Cox regression analysis. Results: Membranous expression of Lewis y and all these CAM-DR-related markers were significantly higher in the resistant group than that of the sensitive group (all P < 0.01). Multivariate regression analysis revealed that high expression of Lewis y, CD44, HE4, integrin α5 and β1 as well as advanced FIGO stage were independent risk factors for chemotherapy resistance (all P < 0.05). Advanced FIGO stage, lymph node metastasis and high expression of Lewis y, CD44, CD147, HE4, integrin α5, β1 were associated with a shorter PFS and OS (all P < 0.05). Moreover, multivariate COX analysis demonstrated that the following variates were independent predictors of worse PFS and OS survival: late FIGO stage (P = 0.013, 0.049), high expressions of Lewis y (P = 0.010, 0.036), HE4 (P = 0.006, 0.013) and integrin β1 (PFS, P = 0.003), integrin α5 (OS, P = 0.019). Conclusion: Membranous expression of Lewis y and CAM-DR-related markers including CD44, CD147, HE4, integrin α5, β1, αv and β3 are associated with the development of chemotherapy resistance. High expression of Lewis y antigen and CAM-DR-related markers including CD44, CD147, HE4, integrin α5 and β1 are independent markers for PFS and OS, in which Lewis y and HE4 are the most significant.
Epithelial ovarian cancer; chemotherapy resistance; prognosis; CAM-DR; Lewis y; HE4
Growth factors are involved in the regulation of hair morphogenesis and cycle hair growth. The present study sought to investigate the hair growth promoting activities of three approved growth factor drugs, fibroblast growth factor 10 (FGF-10), acidic fibroblast growth factor (FGF-1), and basic fibroblast growth factor (FGF-2), and the mechanism of action. We observed that FGFs promoted hair growth by inducing the anagen phase in telogenic C57BL/6 mice. Specifically, the histomorphometric analysis data indicates that topical application of FGFs induced an earlier anagen phase and prolonged the mature anagen phase, in contrast to the control group. Moreover, the immunohistochemical analysis reveals earlier induction of β-catenin and Sonic hedgehog (Shh) in hair follicles of the FGFs-treated group. These results suggest that FGFs promote hair growth by inducing the anagen phase in resting hair follicles and might be a potential hair growth-promoting agent.
The purpose of this study was to identify genes that associated with higher ability of metastasis and chemotherapic resistance in epithelial ovarian carcinoma (EOC) cells. An oligonucleotide microarray with probe sets complementary to 41,000+ unique human genes and transcripts was used to determine whether gene expression profile may differentiate three epithelial ovarian cell lines (RMG-I-C, COC1 and HO8910) from their sub-lines (RMG-I-H, COCI/DDP and HO8910/PM) with higher ability of metastasis and chemotherapic resistance. Quantitative real-time PCR and immunohistochemical staining validated the microarray results. Hierarchic cluster analysis of gene expression identified 49 genes that exhibited ≥2.0-fold change and P value ≤0.05. Highly differential expression of GCET2, NLRP4, FOXP1 and SNX29 genes was validated by quantitative PCR in all cell line samples. Finally, FOXP1 was validated at the protein level by immunohistochemistry in paraffin embedded ovarian tissues (i.e., for metastasis, 15 primary EOC and 10 omental metastasis [OM]; for chemoresistance, 13 sensitive and 13 resistant EOC). The identification of higher ability of metastasis and chemotherapic resistance-associated genes may provide a foundation for the development of new type-specific diagnostic strategies and treatment for metastasis and chemotherapic resistance in epithelial ovarian cancer.
Gene expression profile; Metastasis-associated gene; Chemoresistance-associated genes; Microarray; Epithelial ovarian carcinoma; FOXP1
The objective of the present study was to identify human epididymis protein 4 (HE4) interacting proteins and explore the mechanisms underlying their effect on ovarian cancer cell invasion and metastasis.
HE4 interacting proteins were identified by mass spectrometry and validated by co-immunoprecipitation and pull-down assays. The scratch test, the Transwell assay and animal experiments were used to assess the invasive and metastatic abilities of ovarian cancer cells before and after transfection and HE4 protein treatment. HE4 and annexin II protein expression in epithelial ovarian tissues was detected by immunohistochemistry, and the relation between their expression levels was examined.
Annexin II was identified as an HE4 interacting protein. HE4 and annexin II binding interaction promoted ovarian cancer cell invasion and metastasis. HE4 and annexin II expression levels were significantly higher in malignant epithelial ovarian tissues than in benign and normal epithelial ovarian tissues, and they were higher in tissues with lymph node metastases than in those without. HE4 gene interference downregulated the expression of MAPK and the FOCAL adhesion signaling pathway-associated molecules MKNK2 and LAMB2, and HE4 protein supplementation reversed this effect.
The binding interaction between HE4 and annexin II activates the MAPK and FOCAL adhesion signaling pathways, promoting ovarian cancer cell invasion and metastasis.
Electronic supplementary material
The online version of this article (doi:10.1186/1476-4598-13-243) contains supplementary material, which is available to authorized users.
Ovarian cancer; Human epididymis protein 4; Annexin II; Invasion; Metastasis
Epidemiologic studies have reported inconsistent associations between menarcheal age and ovarian cancer risk. To our knowledge, a meta-analysis for the association between menarcheal age and ovarian cancer has not been reported. Relevant published studies of menarcheal age and ovarian cancer were identified using MEDLINE, EMBASE, and Web of Science through the end of April, 2012. Two authors (T-TG and Q-JW) independently assessed eligibility and extracted data. We pooled the relative risks (RR) from individual studies using a random-effects model and performed heterogeneity and publication bias analyses. A total of 27 observational studies consisting of 22 case-control and 5 cohort studies were included in our analysis. In a pooled analysis of all studies, a statistically significant inverse association was observed between menarcheal age (for the oldest compared with the youngest category) and ovarian cancer risk (RR=0.85; 95% confidence interval (95% CI) 0.75–0.97). The pooled RRs of ovarian cancer for the oldest versus the youngest categories of menarcheal age in prospective and case-control studies were 0.89 (95% CI 0.76–1.03) and 0.84 (95% CI 0.70–0.99), respectively. Inverse associations between menarcheal age and ovarian cancer risk were observed in most sub-groups, but the association was restricted to invasive and borderline serous ovarian cancer. In conclusion, findings from this meta-analysis support that menarcheal age was inversely associated with the risk of ovarian cancer. More large studies are warranted to stratify results by different cancer grading and histotype of ovarian cancer.
menarche; meta-analysis; ovarian neoplasms; reproductive factor
As a well-known neurotrophic factor, nerve growth factor (NGF) has also been extensively recognized for its acceleration of healing in cutaneous wounds in both animal models and randomized clinical trials. However, the underlying mechanisms accounting for the therapeutic effect of NGF on skin wounds are not fully understood. NGF treatment significantly accelerated the rate of wound healing by promoting wound reepithelialization, the formation of granulation tissue, and collagen production. To explore the possible mechanisms of this process, the expression levels of CD68, VEGF, PCNA, and TGF-β1 in wounds were detected by immunohistochemical staining. The levels of these proteins were all significantly raised in NGF-treated wounds compared to untreated controls. NGF also significantly promoted the migration, but not the proliferation, of dermal fibroblasts. NGF induced a remarkable increase in the activity of PI3K/Akt, JNK, ERK, and Rac1, and blockade with their specific inhibitors significantly impaired the NGF-induced migration. In conclusion, NGF significantly accelerated the healing of skin excisional wounds in rats and the fibroblast migration induced by NGF may contribute to this healing process. The activation of PI3K/Akt, Rac1, JNK, and ERK were all involved in the regulation of NGF-induced fibroblast migration.
Beclin 1 is an autophagy-associated protein involved in apoptosis and drug resistance, as well as various malignancies. We investigated the expression of Beclin 1 protein in ovarian epithelial tissues and correlated it with the prognosis of ovarian cancer. Beclin 1 protein expression was determined using immunohistochemistry in 148 patients with ovarian epithelial cancer, 26 with ovarian borderline tumor, 25 with benign ovarian tumor, and 30 with normal ovarian tissue. The relationships between Beclin 1 protein expression and ovarian cancer pathological characteristics were analyzed. The risk factors for ovarian cancer prognosis were analyzed using Cox’s regression model. A survival curve was plotted from the follow-up data of 93 patients with ovarian cancer to analyze the effects of Beclin 1 expression on the prognosis of ovarian cancer. The positive rates of Beclin 1 were significantly higher in ovarian epithelial cancer (148) and borderline tumor (26) than in benign ovarian tumor (25) or normal ovarian tissue (30) (all p < 0.001). The surgical stage and Beclin 1 expression were both independent risk factors for ovarian cancer prognosis (both p < 0.05). Patients with high Beclin 1 levels showed better survival than those with low Beclin 1 levels (p = 0.009). Beclin 1 protein is upregulated in ovarian epithelial cancer and is a prognostic factor of ovarian cancer.
autophagy; Beclin 1; ovarian cancer; prognosis; overall survival
Association between parity and colorectal cancer (CRC) risk has been investigated by several epidemiological studies but results are controversial, yet a comprehensive and quantitative assessment of this association has not been reported so far.
Relevant published studies of parity and CRC were identified using MEDLINE, EMBASE and Web of Science databases through end of April 2013. Two authors independently assessed eligibility and extracted data. Eleven prospective studies reported relative risk (RR) estimates and 95% confidence intervals (CIs) of CRC risk associated with parity. We pooled the RR from individual studies using fixed- or random-effects models and carried out heterogeneity and publication bias analyses.
The summary RR for the ever parity vs. nulliparous was 0.95 (95% CI: 0.88–1.02), with no heterogeneity (Q = 9.04, P = 0.443, I2 = 0.5%). Likewise, no significant association was yielded for the highest vs. lowest parity number (RR = 1.02, 95% CI: 0.89–1.17), with moderate heterogeneity (Q = 17.48, P = 0.094, I2 = 37.1%). Dose-response analysis still indicated no effect of parity on CRC risk and the summary RR of per one livebirth was 0.99 (95% CI: 0.96–1.02), with moderate of heterogeneity (Q = 16.50, P<0.021, I2 = 57.6%). Similar results were observed among all the subgroup analyses. No evidence of publication bias and significant heterogeneity between subgroups were detected by meta-regression analyses.
Results of this dose-response meta-analysis of prospective studies found that there was little evidence of an association between parity and CRC risk.
The main aims of this study were to explore the molecular structural relationship between Human epididymis protein 4 (HE4) and Lewis y antigen by determining their expression patterns and clinical significance in ovarian epithelial carcinoma.
The structural relationship between HE4 and Lewis y antigen was examined using immunoprecipitation and confocal laser scanning microscopy. HE4 and Lewis y were detected in tissues from malignant (53 cases), borderline (27 cases), benign (15 cases) and normal ovarian tissues (15 cases) using immunohistochemical analysis.
HE4 was present in ovarian cancer, benign tumor tissues, ovarian carcinoma cells, and culture medium, and contained Lewis y antigen. Moreover, expression of Lewis y antigen in HE4 from ovarian cancer was higher than that from benign tumor (P<0.05). HE4 possibly exists as two protein isoforms, both containing Lewis y antigen. Our immunohistochemistry data revealed significantly higher positive expression rates of HE4 in malignant ovarian tissues, compared to benign tumor and normal tissue (P<0.05), similar to Lewis y antigen levels in ovarian cancer (P<0.05). Notably, tissues displaying marked expression of HE4 simultaneously expressed high levels of Lewis y antigen. A linear correlation between the expression patterns of HE4 and Lewis y antigen was evident. Consistently, double-labeling immunofluorescence experiments illustrated co-localization of HE4 and Lewis y antigen within the same area.
HE4 contains Lewis y antigen. Our results further demonstrate a close correlation between the expression levels of the two antigens, which are significantly high in ovarian cancer.
This study investigates the expression of Lewis y antigen, integrin αv, β3 in epithelial ovarian cancer tissues. We further evaluate the relationship between their expression and chemotherapy resistance of ovarian cancer and its possible clinical significance.
Tissues of 92 patients with ovarian cancer meeting the inclusion criteria with complete follow-up data were enrolled and divided into chemotherapy resistant group and sensitive group. The expression and relationship of Lewis y antigen and integrin αv, β3 are assessed in paraffin sections using immunohistochemistry and double-labeling immunofluorescence method. Multivariate logistic regression analysis was used to investigate the relationship between age, clinical stage, differentiation, histologic subtype, Lewis y antigen and integrin αv, β3 expression in ovarian cancer patients.
The expression rates of Lewis y antigen and integrin αv in the resistant group, significantly higher than the rates found in the sensitive group (p <0.05). Multivariate analysis showed that the expression of Lewis y antigen, integrin αv and ovarian cancer’s clinical stage were independent, drug resistance-related risk factors. The expression levels of Lewis y antigen and integrin αv, β3 were positively correlated with each other.
A close correlation between Lewis y antigen, integrin αv, β3 and ovarian cancer was observed. Lewis y antigen can influence the biological behavior of a tumor cell as an important composition of integrin αv, β3 by some signal pathway. And the expression of Lewis y antigen, integrin αv and ovarian cancer’s clinical stage are both independent, drug resistance-related risk factors.
Ovarian Cancer; Lewis y Antigen; Integrin αv, β3; Chemotherapeutic Drug Resistance
The aim of this study was to analyze the correlation and clinical significance between the expression of Mucin-1 (MUC1) and the Lewis y antigen with chemoresistance in ovarian epithelial cancers.
Ovarian cancer patients (n = 92) treated at our hospital from May 2005 to July 2009 were divided, according to their treatment and follow-up outcomes, into a resistant group (n = 37) or sensitive group (n = 55). The expression of MUC1 and Lewis y antigen in ovarian cancer tissues was detected using immunohistochemistry and correlated with chemoresistance.
The positive rates of MUC1 and Lewis y antigen in the resistant group were both 91.89%, significantly higher than their positive rates in the sensitive group (65.45% and 69.09%, respectively, and both p < 0.05). MUC1 or Lewis y expression and the pathological stage of the tissue were independent risk factors for chemoresistance (all p < 0.05).
The increased expression of MUC1 and the Lewis y antigen is a significant risk factor for chemoresistance in patients with ovarian epithelial cancer.
ovarian epithelial cancer; MUC1; Lewis y antigen; chemoresistance; immunohistochemistry
Hypertrophic scars (HTS) and keloids are challenging problems. Their pathogenesis results from an overproduction of fibroblasts and excessive deposition of collagen. Studies suggest a possible anti-scarring effect of basic fibroblast growth factor (bFGF) during wound healing, but the precise mechanisms of bFGF are still unclear. In view of this, we investigated the therapeutic effects of bFGF on HTS animal model as well as human scar fibroblasts (HSF) model. We show that bFGF promoted wound healing and reduced the area of flattened non-pathological scars in rat skin wounds and HTS in the rabbit ear. We provide evidence of a new therapeutic strategy: bFGF administration for the treatment of HTS. The scar elevation index (SEI) and epidermal thickness index (ETI) was also significantly reduced. Histological reveal that bFGF exhibited significant amelioration of the collagen tissue. bFGF regulated extracellular matrix (ECM) synthesis and degradation via interference in the collagen distribution, the α-smooth muscle actin (α-SMA) and transforming growth factor-1 (TGF-β1) expression. In addition, bFGF reduced scarring and promoted wound healing by inhibiting TGFβ1/SMAD-dependent pathway. The levels of fibronectin (FN), tissue inhibitor of metalloproteinase-1 (TIMP-1) collagen I, and collagen III were evidently decreased, and matrix metalloproteinase-1 (MMP-1) and apoptosis cells were markedly increased. These results suggest that bFGF possesses favorable therapeutic effects on hypertrophic scars in vitro and in vivo, which may be an effective cure for human hypertrophic scars.
To measure Lewis y antigen and CD44 antigen expression in epithelial ovarian carcinoma and to correlate the levels of these antigens with clinical response to chemotherapy.
The study cases included 34 cases of ovarian carcinoma with resistance to chemotherapeutic drugs, 6 partially drug-sensitive cases, and 52 drug-sensitive cases (92 total).
The rates of expression of Lewis y antigen and CD44 antigen were significantly greater in the drug-resistant group than that in the partially-sensitive or sensitive groups. Surgical stage, residual tumor size and expression of CD44 and Lewis y antigen in ovarian carcinoma tissues were independent risk factors for chemotherapeutic drug resistance.
Over-expression of Lewis y and CD44 antigen are strong risk factors for chemotherapeutic drug resistance in ovarian carcinoma patients.
The ubiquitin-proteasome system and macroautophagy (hereafter referred to autophagy) are two complementary pathways for protein degradation. Emerging evidence suggests that proteasome inhibition might be a promising approach for tumor therapy. Accumulating data suggest that autophagy is activated as a compensatory mechanism upon proteasome activity is impaired.
Autophagy activation was measured using acridine orange staining and LC3 transition. Cell viability and apoptosis were measured using MTT assay and flow cytometry, respectively. Beclin 1 expression vectors or shRNA against Beclin 1 (shBeclin 1) were transfected to investigate the role of Beclin 1 in autophagy activation and cytotoxicity of ovarian cancer cells induced by proteasome inhibitors.
Proteasome inhibitors suppressed proliferation and induced autophagy in ovarian cancer cells. Neither phosphoinositide 3-kinase (PI3K) inhibitors nor shRNA against Beclin 1 could abolish the formation of acidic vacuoles and the processing of LC3 induced by proteasome inhibitors. Moreover, Beclin 1 overexpression enhanced anti-proliferative effects of proteasome inhibitors in ovarian cancer cells.
For the first time, the current study demonstrated that proteasome inhibitors induced PI3K and Beclin 1-independent autophagy in ovarian cancer cells. In addition, this study revealed autophagy-independent tumor suppressive effects of Beclin 1 in ovarian cancer cells.
Proteasome inhibition; Beclin1; Ovarian cancer
To investigate the effect of Lewis y overexpression on the expression of proliferation-related factors in ovarian cancer cells.
mRNA levels of cyclins, CDKs, and CKIs were measured in cells before and after transfection with the α1,2-fucosyltransferase gene by real-time PCR, and protein levels of cyclins, CDKs and CKIs were determined in cells before and after gene transfection by Western blot.
Lewis y overexpression led to an increase in both mRNA and protein expression levels of cyclin A, cyclin D1 and cyclin E in ovarian cancer cells, decrease in both mRNA and protein expression levels of p16 and p21, and decrease of p27 at only the protein expression level without change in its mRNA level. There were no differences in proteins and the mRNA levels of CDK2, CDK4 and CDK6 before and after gene transfection. Anti-Lewis y antibody, ERK and PI3K pathway inhibitors PD98059 and LY294002 reduced the difference in cyclin and CKI expression caused by Lewis y overexpression.
Lewis y regulates the expression of cell cycle-related factors through ERK/MAPK and PI3K/Akt signaling pathways to promote cell proliferation.
Lewis(y) antigen; cell cycle; cyclin; cyclin-dependent kinases; cyclin-dependent kinase inhibitors
To measure Lewis y and integrin α5β1 expression in epithelial ovarian carcinoma and to correlate the levels of these molecules with ovarian carcinoma chemotherapy and prognosis.
The study population included 34 ovarian carcinoma patients with chemotherapeutic drug-resistance, six partially drug-sensitive cases, and 52 drug-sensitive cases (92 total). Immunochemistry was used to determine expression of Lewis y antigen and integrin α5β1 in ovarian carcinoma tissues, and correlation of these molecules with chemotherapy resistance was further investigated, Multi-factor logistic regression analysis was applied to investigate: age, surgical stage, grade, subtype of patient cases, metastasis of lymph nodes, residual tumor size, expression levels of Lewis y antigen and integrin α5β1 correlation with ovarian carcinoma chemotherapy resistance.
The expression rates of Lewis y antigen and integrins α5 and β1 were significantly greater in the drug-resistant group (91.17%, 85.29%, 88.24%) than the partially sensitive (50.00%, 33.33%, 50.00%) or sensitive groups (61.54%, 57.69%, 55.77%). Binary logistic regression analysis revealed that surgical stage, residual tumor size, and expression of integrin α5 and Lewis y in ovarian carcinoma tissues were independent risk factors for chemotherapeutic drug resistance.
Overexpression of Lewis y and integrin α5 are strong risk factors for chemotherapeutic drug resistance in ovarian carcinoma patients.
integrins; Lewis y antigen; ovarian caricinoma; chemoresistance
LeY (Lewis Y) is a difucosylated oligosaccharide carried by glycoconjugates on the cell surface. Elevation of LeY is frequently observed in epithelial-derived cancers and is correlated to pathological staging and prognosis. To study the role of LeY on cancer cells, a stably LeY-overexpressing cell line, RMG-I-H, was developed previously by transfection of the α1,2-fucosyltransferase gene, a key enzyme that catalyzes the synthesis of LeY, into ovarian carcinoma-derived RMG-I cells. Our studies have shown that LeY is involved in the changes in biological behavior of RMG-I-H cells. However, the mechanism is still largely unknown. In this study, we determined the structural relationship and co-localization between LeY and TβRI/TβRII, respectively, and the potential cellular signaling mechanism was also investigated. We found that both TβRI and TβRII contain the LeY structure, and the level of LeY in TβRI and TβRII in RMG-I-H cells was significantly increased. Overexpression of LeY up-regulates the phosphorylation of ERK, Akt and down-regulates the phosphorylation of Smad2/3. In addition, the phosphorylation intensity was attenuated significantly by LeY monoantibody. These findings suggest that LeY is involved in the changes in biological behavior through TGF-β receptors via Smad, ERK/MAPK and PI3K/Akt signaling pathways. We suggest that LeY may be an important composition of growth factor receptors and could be an attractive candidate for cancer diagnosis and treatment.
Lewis Y; p42/44 mitogen-activated protein kinase; phosphoinositide 3-kinase; Smad; transforming growth factor β type I (II) receptor
Lewis y is a difucosylated oligosaccharide carried by glycoconjugates on the cell surface. Elevation of Lewis y is frequently observed in epithelial-derived cancers. This study aimed to detect the expression and clinical significance of the Lewis y antigen and TGF-β1 (transforming growth factor β1) in ovarian epithelial tumors, and to evaluate the correlation between them. Immunohistochemical staining was used to detect the expression of Lewis y antigen and TGF-β1 in 60 cases of ovarian epithelial malignant tumors, 20 cases of borderline ovary tumors, 20 cases of benign ovary tumors and 10 cases of normal ovarian tissues. An immunofluorescence double labeling method was also used to detect the correlation between Lewis y antigen and TGF-β1. The positive rates of Lewis y antigen in ovarian epithelial cancer tissues was 88.33%, significantly higher compared to those of borderline ovarian tumors (60.00%) (P<0.05), benign ovarian tumors (35.00%) (P<0.01) and normal ovarian tissues (0%) (P<0.01). Its expression was not associated with clinical parameters; the positive rates of TGF-β1 in ovarian epithelial cancers were 78.33%, significantly higher compared to those of benign ovarian tumors (65.00%) (P<0.05) and normal ovarian tissues (40.00%) (P<0.05); the positive rates of the TGF-β1 and Lewis y were not associated with metastasis of lymph nodes and histological types, differentiation degree and clinical stage (P>0.05). Expression of Lewis y antigen and TGF-β1 was significantly positively associated with epithelial carcinoma. Close correlation between Lewis y, TGF-β1 and ovarian cancer was observed. Altered expression of Lewis y antigen may cause changes in TGF-β1 expression. Lewis y can increase the growth of ovarian cancer cells and the invasion ability by promoting TGF-β1 abnormal expression and by promoting angiogenesis and a change in its signal transduction pathway. This study provides theoretical evidence for the development of ovarian cancer biological treatments.
ovarian epithelial carcinoma; transforming growth factor β1; Lewis y; immunohistochemistry; immunofluorescence double labeling method
This study aimed to investigate the molecular structural relationship between cell adhesive molecule CD44 and Lewis y antigen, and determine the effects of Lewis y antigen on CD44-mediated adhesion and spreading of ovarian cancer cell line RMG-I and the Lewis y antigen-overexpressed cell line RMG-I-H.
The expression of CD44 in RMG-I and RMG-I-H cells before and after treatment of Lewis y monoclonal antibody was detected by immunocytochemistry; the expression of Lewis y antigen and CD44 was detected by Western Blot. The structural relationship between Lewis y antigen and CD44 was determined by immunoprecipitation and confocal laser scanning microscopy. The adhesion and spreading of RMG-I and RMG-I-H cells on hyaluronic acid (HA) were observed. The expression of CD44 mRNA in RMG-I and RMG-I-H cells was detected by real-time RT-PCR.
Immunocytochemistry revealed that the expression of CD44 was significantly higher in RMG-I-H cells than in RMG-I cells (P < 0.01), and its expression in both cell lines was significantly decreased after treatment of Lewis y monoclonal antibody (both P < 0.01). Western Blot confirmed that the content of CD44 in RMG-I-H cells was 1.46 times of that in RMG-I cells. The co-location of Lewis y antigen and CD44 was confirmed by co-immunoprecipitation. The co-expression of CD44 and Lewis y antigen in RMG-I-H cells was 2.24 times of that in RMG-I cells. The adhesion and spreading of RMG-I-H cells on HA were significantly enhanced as compared to those of RMG-I cells (P < 0.01), and this enhancement was inhibited by Lewis y monoclonal antibody (P < 0.01). The mRNA level of CD44 in both cell lines was similar (P > 0.05).
Lewis y antigen strengthens CD44-mediated adhesion and spreading of ovarian cancer cells.
To detect the expression and clinical significances of Lewis y antigen and integrin αv, β3 in epithelial ovarian tumors, and to explore the expression correlation between Lewis y antigen and integrin αv, β3.
Immunohistochemical staining was performed in 95 cases of epithelial ovarian cancer, 37 cases of borderline tumors, 20 cases of benign tumors, and 20 cases of normal ovarian tissue, for the detection of Lewis y antigen and integrin αv, β3 expressions, and to analyze the relationship between Lewis y antigen and integrin, and the relationship between clinical and pathological parameters of ovarian cancer. In addition, immunofluorescence double labeling was utilized to detect the expression correlation between Lewis y antigen and integrin αv, β3 in ovarian cancer.
In epithelial ovarian tumors, the expression rate of Lewis y antigen was 81.05%, significantly higher than that of borderline (51.53%) (P < 0.05) and benign (25%) (P < 0.01) tumors, and normal ovarian tissues (0) (P < 0.01). The expression rate of integrin αv, β3 in malignant epithelial ovarian tumors was 78.95% and 82.11%, respectively, significantly higher than that of the borderline (45.94%, 40.54%) (both P < 0.05), benign group (10.00%, 15.00%) (both P < 0.01) and normal ovary group (5%, 15%) (both P < 0.01).
Lewis y and integrins αv, β3 are relevant to pelvic and abdominal diffusion and metastasis of ovarian cancer cells, suggesting that these two molecules mediate a boosting function for tumor metastasis.
epithelial ovarian tumor; integrin αvβ3; Lewis y antigen; immunohistochemistry; immunofluorescence double labeling method
This study aimed to measure and correlate the expression of insulin-like growth factor receptor-1 (IGF-1R) and the Lewis(y) antigen in ovarian cancer cell lines and tissue samples.
Reverse transcriptase PCR (RT-PCR), Western blotting, immunoprecipitation, immunohistochemistry, and immunofluorescence double-labeling techniques were applied to detect and measure the expression of Lewis(y) and IGF-1R.
In α1,2-fucosyltransferase (α1,2-FT)-transfected cells, IGF-1R expression was significantly upregulated compared with cells that do not overexpress α1,2-FT (P < 0.05). The amount of Lewis(y) expressed on IGF-1R increased 1.81-fold in α1,2-FT-overexpressing cells (P < 0.05), but the ratio of Lewis(y) expressed on IGF-1R to total IGF-1R was unaltered between two cells (P > 0.05). In malignant epithelial ovarian tumors, the positivity rates of Lewis(y) and IGF-1R detection were 88.3% and 93.33%, respectively, which is higher than the positivity rates in marginal (60.00% and 63.33%, all P < 0.05), benign (33.00% and 53.33%, all P < 0.01), and normal (0% and 40%, all P < 0.01) ovarian samples. No correlations were detected in positivity rates of Lewis(y) or IGF-1R expression with respect to clinicopathological parameters in ovarian cancers (all P > 0.05). Both IGF-1R and Lewis(y) were highly expressed in ovarian cancer tissues, and their expression levels were positively correlated (P < 0.05).
Overexpression of Lewis(y) results in overexpression of IGF-1R. Both IGF-1R and Lewis(y) are associated with the occurrence and development of ovarian cancers.
epithelial ovarian tumor; Insulin-like growth factor receptor-1; Lewis(y) antigen; immunohistochemistry; immunofluorescence double labeling method
Epithelial carcinomas of the ovary exhibit the highest mortality rate among gynecologic malignancies. Studies found that the metabolism of glycolipids or carbohydrates is associated with acquirement of anticancer drug-resistance by cancer cells. This study was to characterize possible involvement of Lewis Y (LeY) antigen in the drug-resistance of cancer cells. We transfected the α1,2-fucosyltransferase gene into human ovarian carcinoma-derived RMG-1 cells and established RMG-1-hFUT cells with enhanced expression of LeY. We determined the effects of docetaxel on the survival of cells by MTT assaying and observed the apoptosis of cells in the presence of docetaxel by flow cytometric analysis and by transmission electron microscopy. Plasma membranes and intracellular granules in RMG-1-hFUT cells were stained with anti-LeY antibody, the intensity of the staining was higher than that in control cells. The RMG-1-hFUT cells exhibited higher resistance to docetaxel than the control cells with regard to the docetaxel concentration and time course. After treatment with 10 μg/mL docetaxel for 72 h, the control cells, but not RMG-1-hFUT, contained abundant positively stained cell debris due to disintegration of the cytoskeleton. On transmission electron microscopy, although the control cells treated with docetaxel as above showed the following morphology, i.e., absence of villi, cells shrunken in size, pyknosis, agglutinated chromatin and cell buds containing nuclei in the process of apoptosis, the RMG-1-hFUT cells showed only agglutinated chromatin and vacuoles in the cytoplasm. In summary, cells with enhanced expression of LeY were shown to acquire docetaxel-resistance, indicating the possible involvement of glycoconjugates in the drug-resistance.
ovarian cancer; Lewis Y antigen; docetaxel; drug resistance
Lewis y (LeY) antigen is a difucosylated oligosaccharide carried by glycoconjugates on the cell surface. Overexpression of LeY is frequently observed in epithelial-derived cancers and has been correlated to the pathological staging and prognosis. However, the effects of LeY on ovarian cancer are not yet clear. Previously, we transfected the ovarian cancer cell line RMG-I with the α1,2-fucosyltransferase gene to obtain stable transfectants, RMG-I-H, that highly express LeY. In the present study, we examined the proliferation, tumorigenesis, adhesion and invasion of the cell lines with treatment of LeY monoclonal antibody (mAb). Additionally, we examined the expression of TGF-β1, VEGF and b-FGF in xenograft tumors. The results showed that the proliferation and adhesion in vitro were significantly inhibited by treatment of RMG-I-H cells with LeY mAb. When subcutaneously inoculated in nude mice, RMG-I-H cells produced large tumors, while mock-transfected cells RMG-I-C and the parental cells RMG-I produced small tumors. Moreover, the tumor formation by RMG-I-H cells was inhibited by preincubating the cells with LeY mAb. Notably, the expression of TGF-β1, VEGF and b-FGF all increased in RMG-I-H cells. In conclusion, LeY plays an important role in promoting cell proliferation, tumorigenecity and adhesion, and these effects may be related to increased levels of growth factors. The LeY antibody shows potential application in the treatment of LeY-positive tumors.
Lewis y; ovarian cancer; proliferation; tumorigenecity; adhesion; inhibition
Lewis (y) antigen is a difucosylated oligosaccharide present on the plasma membrane, and its overexpression is frequently found in human cancers and has been shown to be associated with poor prognosis. Our previous studies have shown that Lewis (y) antigen plays a positive role in the process of invasion and metastasis of ovarian cancer cells. However, the mechanisms by which Lewis (y) antigen enhances the invasion and tumor metastasis are still unknown. In this study, we established a stable cell line constitutively expressing Lewis (y) antigen (RMG-1-hFUT) by transfecting the cDNA encoding part of the human α1,2-fucosyltransferase (α1,2-FUT) gene into the ovarian cancer cell line RMG-1, and investigated whether Lewis (y) antigen regulates the expression of matrix metalloproteinase-2 (MMP-2) and MMP-9, and tissue inhibitors of metalloproteinases (TIMP-1) and TIMP-2. We found that RMG-1-hFUT cells exhibited higher invasive capacities than their control cells. In addition, expression of TIMP-1 and TIMP-2 was down-regulated and expression of MMP-2 and MMP-9 was up-regulated. Anti-Lewis (y) antigen antibody treatment significantly reversed the expression of TIMP-1, TIMP-2, MMP-2 and MMP-9. Taken together, we provide the first evidence that down-regulation of TIMP-1 and TIMP-2 and up-regulation of MMP-2 and MMP-9 represents one of the mechanisms by which Lewis (y) antigen promotes cell invasion.
Lewis (y) antigen; matrix metalloproteinases; tissue inhibitors of metalloproteinases; invasion